Herb Power in the Air: Evaluating the Effectiveness of Citrus sinensis (Orange Peel) Extract Candles as a Natural Fruit Fly Repellent

Grade:

6

Teacher:

Shermaine Dela Rosa

Fruit flies (Drosophila melanogaster) are common household pests that are often controlled using chemical insect sprays, which may be harmful to humans, pets, and the environment. Because of these concerns, we investigated a natural alternative using orange peel (Citrus sinensis) extract. Orange peels contain natural compounds such as limonene and essential oils that can affect insect behavior. In this study, we tested whether soy wax candles infused with orange peel extract could influence fruit fly attraction and mortality. Orange peels were dried, soaked in alcohol, and concentrated using a rotary evaporator to preserve bioactive plant compounds. The extract was infused into handmade soy wax candles at four concentrations: 0% (control), 25%, 50%, and 100%. Each candle was tested in a container with ten fruit flies, and observations were recorded every five minutes for twenty minutes. We measured fruit fly attraction rate (number of flies within 5 cm of the candle) and mortality percentage. The results showed that the 50% concentration candle produced the highest attraction rate during the first 5–10 minutes, while attraction decreased over time for all treatments. Mortality increased mainly with longer exposure time, and the control candle produced mortality levels similar to the extract candles. These results suggest that orange peel extract candles affect fruit fly behavior, but the extract functions more as a behavioral attractant than a repellent. Overall, this study shows that orange peel extract may be better used in fruit fly traps as a safer and more environmentally friendly alternative to chemical insect sprays.

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